“Mir zaynen do!” (“We are here!”) The defiant Yiddish refrain of a Polish Jewish partisan song, written in the darkest days of the second world war, rings out in the winter sunlight, echoing between a sombre monument to the heroes of the Warsaw ghetto rising and the shining, brand-new Museum of the History of Polish Jews. The words are spoken, with passion, by a Polish Jewish survivor of Auschwitz, Marian Turski, who remained in Poland after the war. Here, still here, or here again, where so much of European Jewish life was lived for so many centuries. If an electric tingle does not go up your spine at such a moment, there is something wrong with your spine.

Then we pass into the museum, through a giant twisting canyon of sand-like stone, conceived by the architect to recall Moses’s parting of the Red Sea. Down a curling marble staircase we find a multimedia exhibition that documents 1,000 years of Polish Jewish history. The Holocaust is there, of course, but the story does not begin or end with the Holocaust. “It is not a museum of the Shoah,” says the president of Israel, at this opening ceremony. “It is a museum of life.”

To anyone who knows anything about the tortured history of Polish-Jewish relations since the second world war, this whole event felt like a small miracle. Before I travelled to Poland for the first time, 35 years ago, I visited a small bookshop in central London, to buy some books about Poland. “Why on earth do you want to go there?” asked the bookseller, and then quoted some Yiddish words from his Polish Jewish mother which roughly translated as: “Why would you go to the accursed land?” I remember a private dinner in Washington when Jan Nowak, a hero of the Polish resistance to Nazism, was confronted by a US congressman with the familiar charge-sheet of Polish antisemitism before the starter was even on our plates. I recall a conference in Oxford where Claude Lanzmann, the director of the unforgettable film Shoah, told an elderly Polish historian who had himself survived Auschwitz – as a Polish political prisoner, not a Jew condemned to extermination – that the fact of surviving Auschwitz did not mean one was intelligent.

If I was given a dollar for every time a casual conversation in the west about Poland has turned within minutes to Polish antisemitism, I would be a millionaire. But equally, if I was given a euro for every time I have heard or read in Poland some piece of contorted, resentful denial about the true extent of Polish antisemitism, before, during and after the second world war, I would also be a rich man.

Now we have reached this once almost unimaginable better place in the relations between, and the historical, cultural and individual intermingling of, Poles and Jews. Why has it come about? First, due to the efforts of women and men of goodwill who for decades have explained, often to deaf ears on both sides, that we can only get beyond those hostile stereotypes when we understand the full historical complexity. Second, thanks to the freedom that Poland achieved 25 years ago. Only when Poland was itself no longer a victim of history – stuck behind the iron curtain, under Soviet domination – could a larger part of Polish society begin to face up to the excruciating truth that a victim can also be a victimiser. For a part of Polish society most certainly did victimise the Jews, in pogroms during and immediately after the war, and in a final, communist-manipulated spasm of hate in 1968.

Such a psychology of denial is not unique to Poland. For example, much of Israeli society today apparently has difficulty facing up to its own excruciating truth. The fact that the Jews were the greatest victims of genocidal European barbarism in the 20th century – something no European should ever forget – does not mean that Israelis are not themselves victimising Palestinians today. Of course there are many important differences between the Polish and Israeli cases, but the general point stands: historical victims can also be victimisers.

This long-delayed Polish confrontation with its own difficult past has been turbulent. The controversy sparked by the historian Jan Gross’s account of how, in summer 1941, Polish inhabitants of the village of Jedwabne burned their Jewish neighbours to death in a village barn, was often furious. But the truth has not only been approached through polemical confrontation. Thousands of Poles have quietly unearthed their own Jewish family roots. Young Poles with no Jewish roots have rediscovered the rich heritage of Polish Jewish culture – publishing books, mounting exhibitions, organising debates.

There is now a very small-scale but vibrant Jewish life in Poland. When I arrived in Warsaw on Sunday night the whole translucent new museum was alight and alive with a social gathering of Polish Jews. It is impossible to say with confidence how many Jews live in Poland today, not least because it must be for each individual to decide whether she or he will self-identify as a Jew, or Jewish, or “of Jewish origin”, or none of the above.

While an official census in 2002 put the number of those who identified themselves as being of Jewish nationality (without being given the option of specifying both Polish and Jewish) at just 1,100, that in 2011 registered some 2,000 who listed Jewish as their first “national-ethnic” identity, and a further 5,000 who gave Jewish as their second identity. Unofficial estimates range from 10,000 to as high as 100,000. This is not counting most of the 20,000 or more Israelis who have taken Polish citizenship – and hence have full access to the whole EU – but generally don’t live in Poland. So nobody really knows. Yet the refrain “We are here” is clearly more true today than it has been for a long time.

Let no one have any illusions. There are still weary leagues to travel down this long and winding road, with accidents waiting to happen and probably more road rage to come. For all that, the dignified opening of this museum does mean that the road has reached a crest, from which we can peer towards a new horizon: not the promised land, to be sure, but certainly no longer an accursed land. And I, for one, will never forget that spine-tingling refrain, echoing in Warsaw’s winter sunlight: Mir zaynen do!

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